Problem with rest position and pose mode
Blender does not run scripts that are part of .blend files automatically, which unfortunately includes the scripts that run Rigify-based rigs together. Blender has to be told that this file is ok, and to run its included Python.  

At the top of your first screenshot, there is "Auto Run Disabled" next to the button "Reload Trusted".  Click Reload Trusted, it will reload the file with scripts enabled.

When you load the file with the "open .blend" option under "file", there is the checkbox labeled "Trusted Source", which should also allow scripts to run and for this rig to not flip out.